quarta-feira, janeiro 07, 2009

Ilusões quânticas ou quânticos iludidos?

Ainda do physics Arxiv Blog:

Quantum consciousness, a phrase that sends most eggheads running for the hills, is currently on a roll. A coupla months back, Efstratios “Moussaka” Manousakis of Florida State University in Tallahassee published a paper suggesting that a certain kinda optical illusion could be explained in quantum terms.

The optical illusion in question is the double image flip like the one above which switches from one scene to another in the viewer’s mind. Neuroscientists have always wondered why ya can’t see both images at the same time.

The new thinkin is that the image exists in a kinda quantum superposition of both states. When this state collapses, it gives the observer the sense that he or she is lookin at one scene or the other (but not both). That sounds interesting but the impressive thing about Moussaka’s work is that it succesfully predicts the rate at which this flipping occurs in humans.

Now quantum physicist Henry “Goose” Stapp from the Lawerence Berkeley National Lab in Berkeley has entered the fray. His contribution is to tackle some of the criticism that has been levelled at Moussaka’s idea, in particular, the charge that in our warm, wet brains, decoherence destroys any quantum effects before they even get going.

Not so says Stapp. He argues that there exists a kinda twilight zone in which quantum phenomena can follow classical trajectories without being influenced by decoherence. So the collapse that triggers the conscious observation of one image or the other is essentially a classical phenomena that is steered by a few key quantum rules. It is therefore immune to decoherence.

Interesting idea but you can almost hear neuroscientists sucking their teeth as they read it. Stapp’s gonna need some more evidence and lots of it before an idea like this can become mainstream.

Ref: arxiv.org/abs/0710.5569: The Quantum-Classical and Mind-Brain Linkages: The Quantum Zeno Effect in Binocular Rivalry

Para modelos com redes neurais clássicas, ver aqui no Arxiv ou no Physica D se você tem assinatura:

Lá eu explico ilusões com multiestabilidade (mais de 10 imagens coexistindo, ver abaixo) com uma frequência acelerada em relação à biestabilidade clássica (cubo de Necker). Não acho que as idéias de Manousakis possam fazer isso...

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